This produces currents of air.The other paper was also in Rollo's handwriting, and was as follows If the entry was full of water, and the parlor full of air, and the walls were water gray cheeked thrush tight, and you were to open the door between the two rooms, the water would flow into the parlor down below, and the air would flow into the entry up above.Now hold it up a little higher, said his mother.And why does it make gray cheeked thrush it light? asked his mother.Because it swells it it makes it expand so that the same quantity of air spreads over a greater space and this makes it lighter, But cool or cold air is heavier, because it is more condensed.' 'Well,' said the gentleman, 'I am very sorry gray cheeked thrush if it is.He came down to the ground without being hurt at all.I mean to gray cheeked thrush ask my father, said Rollo.A few days after this, there commenced a long storm of rain.He succeeded very well in getting pieces completely on fire but, after gray cheeked thrush they were dropped into the hole, they would not burn.Rollo obeyed, and he found that it was still pressed in, but not so hard.Suppose the entry were full of water, and the parlor full of air, gray cheeked thrush and the door was shut, and the door and the walls were water tight.They sometimes collect different kinds of air in glass jars, and then let a candle down in, and see whether it will go out.They all look clear, just as if there was nothing gray cheeked thrush in the jars but when you let a candle down in, in some it burns just the same as before in some it burns brighter and in some it goes out.So Rollo opened the door, and held his tuft in the passage way and he found that the air was pressing in very strongly through the open space.